[darcs-users] Evil sources

[David Leuschner]

Hi all,

I just helped a coworker patiently waiting several minutes for a
"darcs pull" to give him some output.  Darcs is terribly slow and
performance tuning won't help here.  The cause was that
_darcs/prefs/sources contained an HTTP repository URL with an IP
Address but the host was down.   When I turned on --debug-verbose it
was clear to me what the problem is.  I often help with such problems
- but I'd rather not and as a regular Darcs users you're annoyed if
something like that happens.  Because the fix is so simple (if you
know what to do) I didn't bother to report it as a bug.  In fact: I
won't complain anymore beyond this email.  But I can understand why
people use git instead.  Without turning-on debugging output I
couldn't say why pulling a few simple, small patches from a fast
remote server is taking so long.  And even if I turn on debugging
nobody can expect a user to understand why Darcs is so smart that it
tries to access a different host that is down. I don't know why there
was no timeout or if the timeout took too long or if Darcs tried the
same host several times.  The fact is: a regular, experienced darcs
user can easily get the impression that Darcs is slow or doesn't work
at all.

I understand that the different sources are necessary for lazy
repositories.  I think we have to assume that we won't get good
timeout behavior all of the time.  And even if the cause might be DNS
or a firewall: the problem is, that a) the user doesn't know it has
nothing to do with URL she gave on the command line and b) she doesn't
know how to fix it.

I think Darcs should be changed that it

 1. outputs a message if it tries to access a repository other than
that given on the command line

 2.

-- 
David Leuschner
Kartäuserstraße 51b
79102 Freiburg
Tel.: +49 761 4296027